FC60 DISK ARRAY

[Andrew Luis Arruza]

I have connected our FC60 Disk Array to three servers via Fibre Channel.
Is there a way I can see exactly what server is using which disks in the array?
I believe we have run into the problem of writing over data that is being used by one server when we extend the volumne on another.
If someone can point me in the correct direction it would be greatly appreciated.
Any/all help is welcome.
Andy

[Anthony deRito]

The product doco for the FC60 is located at:

http://www.hp.com/essd/FC60_documentation.html


Tony

[Stuart McNabb · Accepted solution]

G'day Andy,
From the sounds of things you are in a small SAN environment, with maybe a FC Hub or Switch in the middle providing the connectivity to the FC60. If you have a Hub or a switch running in AL ( Quickloop ) mode the problem is that everything on the loop can see the Luns on the FC60. One way you can at least filter this is via the switches by zoneing off the WWN of the controllers in the FC60 to certain systems. This currently can't be done at the LUN level on the switches. I believe Brocade are working on this and maybe in a future release of the switch firmware it may provide it. You can download from www.software.hp.com the FC manager, this provides software Lun masking, but it must be installed on each system on the SAN to be effective.

As for systems writing over data, it's very hard to monitor traffic over FC without a switch. A system can requst to write to any disk it can see.. however, if the Luns are part of a LVM volume, this should not be possible as the VG must be activated for the system to talk to it. HP-UX has no real locking mech for VG's without ServiceGuard installed. So in theory on your San a system can activate a VG while it's mounted on another system. This will cause corruption and non synced Superblocks..

What I would confirm is the mapping of VGs to the Luns on the system. If you have shared Volume groups, confirm they are only activated on one node at a time. Also, be aware that there is nothing stopping someone on one of the systems noting that one of the disks are not in a VG on that system and pvcreateing it, thus destroying the PV on another system ( this will only show up after the VG is reactivated only the other host ). If you are talking to raw disk devices.. well you are going to have to check what is writing to it from the host end.

What type of corruption are you seeing? What are the filesystem types on the FC60 i.e. Raw, Vxfs??

Hope this helps

Stuart